An interventional study of Herbiotics Oral + Ent Probiotic and Placebo in Hypertension, Cardiovascular Diseases and Diabetes, sponsored by Wake Forest University. Recruiting at 1 site in United States. Open to participants aged 18 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-07-19.
Sponsored by Wake Forest University · Not applicable, Interventional, and Basic science
Nitric Oxide (NO) is an important molecule that is produced naturally in the body and that helps maintain healthy blood flow. Low availability of NO contributes to many diseases while administration of NO is therapeutic.
In addition to being made naturally in the body, NO can be obtained through the diet via the Nitrate-Nitrite-NO cycle. Nitrate, which is abundant in green leafy vegetables and beetroot juice, is partially converted to nitrite by oral bacteria. The nitrate and nitrite are taken up into the blood and nitrite is converted into NO. Remaining nitrate in the blood is taken back up into the mouth by salivary glands and the cycle continues. Emerging studies suggest that the Nitrate-Nitrite-NO cycle may contribute to cardiovascular health. In addition, there have been many studies where dietary nitrate is given to increase NO and treat various conditions.
The current study rests on the premise that the quality of the oral microbiome plays a major role in the Nitrate-Nitrite-NO cycle and hence cardiovascular health and the efficacy of dietary nitrate interventions. Investigators have begun to identify oral bacterial species that are effective nitrite producers as well as though that are nitrite depleters (those that interfere with nitrite production from nitrate).
In laboratory experiments, certain bacterial species have been shown to block nitrate to nitrite conversion by other oral bacteria. These nitrite depleting species are found in a commercially available oral probiotic designed to improve oral health. The purpose of this study is to examine if use of the probiotic negatively affects the Nitrate-Nitrite-NO cycle. Nitrate to Nitrite conversion will be assessed by measuring plasma levels of nitrite before and after consumption of nitrate-rich beetroot juice. Dietary nitrate to plasma nitrite conversion will assessed at baseline and after one week of consumption of the probiotic or a placebo (follow-up). The primary hypothesis of this study is that participants that consume the probiotic will have lower nitrate to nitrite conversion at follow-up compared to baseline and that there will be no significant change in nitrate to nitrite conversion between baseline and follow-up for participants who consume the placebo.
While this study does not aim to treat any specific disease, it is intended to elucidate a basic physiological function that may be relevant to cardiovascular health and certain NO-based therapeutics.
Background
Nitric oxide (NO) plays critical roles in a myriad of cellular and molecular mechanisms regulating physiology and function of various organs and systems.1,2 Low NO bioavailability contributes to pathology in multiple diseases including hemolytic anemias,3 malaria,4,5 transfusion of older stored blood,6,7 chronic heart failure,8 atherosclerosis,9 and diabetes.10 Recent reports suggest that the oral microbiome is linked with regulating NO homeostasis through the action of certain bacteria that have an ability to reduce nitrate to nitrite.11-15 Nitrite is then further reduced to NO through a variety of mechanisms in different tissues.16,17 Plasma nitrate is taken up back into the oral cavity by salivary glands so that the nitrate-nitrite-NO cycle provides sustained increases in NO bioavailability. Many clinical studies have used dietary nitrate as a source of NO through nitrite conversion.18-24 However, there is substantial variability in the clinical outcomes due to dietary nitrate intake and this is reflected in variability in the amount of nitrate converted to plasma nitrite.13,24-29 30. The variability and hence a large overall limitation in efficacy of dietary nitrate based treatments has been attributed to the capacity of the oral microbiome to reduce nitrate to nitrite.24-27 Preliminary work has begun to identify bacterial strains that are efficient nitrate to nitrite converters as well as those that actually inhibit nitrate to nitrite conversion.31,32 The efficiency of the nitrate-nitrite-NO cycle and the role of oral bacteria may contribute to normal health.11 Thus, understanding the variability in nitrate to nitrite conversion and aspects of the oral microbiome could lead to improvements in normal cardiovascular health. In addition, in order to maximize benefits from dietary nitrate interventions, we need to understand factors of the oral microbiome that affect nitrate to nitrite conversion. The investigators have recently discovered that several species of Lactobacillus produce a metabolite that blunts nitrate to nitrite conversion by other oral bacteria in vitro. Several of these Lactobacillus species are the main component of a commercially available oral probiotic, https://www.amazon.com/Dental-Probiotics-Breath-Gingivitis-Throat/dp/B096SZSFFS
Purpose
The purpose of this study is to determine if Lactobacillus will blunt dietary nitrate to plasma nitrite conversion.
The investigators hypothesize that the presence of oral Lactobacillus will blunt the conversion of dietary nitrate to plasma nitrite and will test this by comparing the conversion before and after use of this probiotic.
The main hypothesis rests on the auxiliary hypothesis that use of the oral probiotic will results in increased abundance of Lactobacillus in the oral cavity and will test this through genomic sequencing.
Methods OPEDNPN All eligible volunteers will be consented after learning about the study and agreeing to participate. Volunteers will be randomly assigned to one of two groups: (1) Probiotic and (2) Placebo. A total of 20 volunteers (10 per group) will participate in the study. The only difference for participants for each group will be whether they receive the placebo or probiotic.
All volunteers will participate in two visits: (1) Visit 1, baseline and (2) Visit 2, follow up. At each visit, volunteers will report to the Olin Physical Lab room 208 after having fasted for 3 hours prior. They can drink water one hour before the visit. Participants will be instructed not to use anti-bacterial mouthwash the day of the visit. The participant will be asked to provide 4 mL of saliva and a study team member will collect a bacterial sample from the posterior dorsal surface of their tongue (as described below). These samples will be frozen at -80 degrees for genetic analysis and identification of bacterial strains.
After saliva and tongue samples are collected, blood will be drawn (as described below) for plasma nitrite and nitrate determination. This blood sample will be the "pre-" sample collected at baseline and follow-up. Volunteers will then drink one 70 mL Beet it Sport Nitrate 400 shot (https://www.beet-it.us/pages/beet-it-sports). A "post-" blood draw will be collected 2.5 hours after consumption of the beetroot juice.
At Visit 1, after the second blood draw, volunteers will receive 7 days worth of either probiotic or the placebo. Volunteers will consume the probiotic (or placebo) as indicated by the manufacturer of the probiotic once a day. On day 8, the volunteers will return for visit 2.
The data will include (1) baseline and follow-up analysis of oral bacterial strains and (2) Pre- and post-beet juice consumption plasma nitrite and nitrate levels. The investigators hypothesize that the abundance of Lactobacillus will be higher at follow-up compared to baseline for volunteers taking the probiotic but that there will be no change in the placebo group. The investigators also hypothesize that the change in plasma nitrite (post minus pre) will be lower at follow-up than at baseline for volunteers taking the probiotic but that there will be no change in the placebo group.
Study Materials (all commercially available):
Risks Approximately 10 mL of blood will be drawn from patients willing to participate. This will be done in the usual fashion, preparing the venipuncture site with the local anesthetic EMLA, then drawing blood through a small gauge (23 or 21) butterfly needle. Drawing blood from a vein may be associated with discomfort or bruising at the site of needle puncture. Rarely, fainting or infection at the site of needle puncture may occur. All blood will be drawn from a person trained in phlebotomy. There will be no way to trace the blood back to the donor.
There are no known health risks for donating saliva or tongue scrapings from individuals who will be included in the study. There is a very minimal risk of linking individuals to the study. There will be no way to trace the saliva or tongue scrapings back to the donor.
Protections Against Risk Strategies for protection against risk. To protect privacy of participants and confidentiality of research data, no personal information regarding individual participants will be linked to the in vitro studies.
Plans for medical attention. In case of injury (which is extremely unlikely) as a result of saliva donation, the individuals will be instructed to contact their physician and medical care will be offered and charged to available research coverage maintained at Wake Forest School of Medicine.
In case of injury as a result of blood drawing, the patients will be instructed to contact their physician and medical care will be offered and charged to available research coverage maintained at Wake Forest School of Medicine. Blood drawn on the Reynolda campus is not a clinical setting, but blood will be drawn by trained phlebotomists with years of experience who maintain their training.
Any unanticipated problems, serious and unexpected adverse events, deviations or protocol changes will be promptly reported by the principal investigator or designated member of the research team to the IRB and sponsor or appropriate government agency if appropriate.
Incidental Findings. No incidental findings are expected to be discovered in this study as measures of bacterial nitrate reduction are not currently of clinical relevance so a strange, individual result in that measure would not be worth communicating.
Sample size assessment and statistical analysis
The investigators plan to enroll 10 participants who receive the probiotic and 10 participants who receive the placebo. The investigators hypothesize that, using a paired t-test, participants taking the probiotic will have significantly (P \< .05) lower change in plasma nitrite (post minus pre) at follow up compared to baseline while there will be no significant effect of the placebo (paired t-test).
The Investigators calculated that they would have 80% power to measure a 75% decrease in the change in nitrite at follow-up compared to baseline for the probiotic group with 10 participants per group (Continuous endpoint Two independent samples). The investigators assumed a 60% standard deviation in the change in nitrite for follow-up vs baseline based on previous data from our lab.
6,114 studies on the registry are indexed under Hypertension; 912 are open to participants now.
This study's planned enrollment of 20 is below the median of 100 across 4,575 interventional studies indexed under Hypertension.
Browse Hypertension studies →Wake Forest University is the lead sponsor of 118 studies on the registry; 7 are open to participants now.
Of its 31 completed or terminated interventional studies of FDA-regulated products, 27 (87%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will take the commercially available oral probiotic (Herbiotics Oral + Ent Probiotic) twice a day for 7 days as instructed by the manufacturer. This entails one lozenge twice a day taken by mouth and slowly chewed or allowed to melt in the mouth.
Dietary Supplement: Herbiotics Oral + Ent Probiotic
Participants will take the commercially available Honest Placebo Pills by Zeebo twice a day for 7 days. This entails one tablet twice a day taken by mouth and slowly chewed or allowed to melt in the mouth.
Dietary Supplement: Placebo
Chewable Tablets containing Lactobacillus species.
Honest Placebo Pills by Zeebo
Dietary Nitrate Conversion to Plasma Nitrite
The main outcome is the plasma nitrite level 2.5 after consuming Beet Juice minus the plasma nitrite level prior to drinking beet juice. Blood will be collected prior to drinking one Beet it Sport shot and 2.5 hours after drinking the shot. Plasma nitrite will be measured from these blood draws. This outcome will be measured at two visits: baseline and followup (day 8) and the increase in plasma nitrite at the two visits will be compared. Between the two visits the participants will consume the Probiotic or Placebo for 7 days.
Time frame: The two visits will be 8 days apart.
Percentage Lactobacillus
Oral bacterial species will be determined from saliva and tongue scrapings at both visits prior to beet juice consumption. The percentage abundance of Lactobacillus will be determined at each visit and compared to each other. Between the two visits the participants will consume the Probiotic or Placebo for 7 days.
Time frame: The two visits will be 8 days apart.
Plan to share: Yes — Only a coded participant identifier will be shared with a scientific collaborator. The participant identifier will not be traceable to the individual participant. It is only used to correlate data collected at different sites.
Supporting information: Analytic code
Time frame: When saliva and tongue scrapings are sent to University of South Florida for microbiome analysis, the samples will include the code.
Access criteria: Scientific investigators on the team will have access to the codes - not any links to the original participants.
Started Jun 2024 (actual). Primary completion is estimated for May 2025, 11 months after the start.
Of 1,403 non-industry interventional studies with no phase under Hypertension, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 41. This study's planned 11 months is below that.
Counting every sponsor, half of 1,498 studies reached it within 23 months; a quarter within 10 and three quarters within 41.
How these figures are worked out, and which studies are left out of them.
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